Compound steam-engine.



N0. 64U,2l8. Patented Jan. 2, I900. E. McCONVlLLE.

CDMPOUND STEAM ENGINE.

(Application filed Apr. 20, 1899.) (No Model.) 4 Sheets-Sheet L Iuen/Zor W 7% @W (264M THE NORRIS PEYIHS c0. Pnmuuma. wasnwcron, o. c

Nu. 649,2!8. Patented Jan. 2, I900. E. McCUNVILLE.

COMPOUND STEAM ENGINE.

(Application filed Apr. 20, 1899.) (l'lo Model.) 4 Sheets$heet 2.

N0. 640,2!8. Patented Ian. 2, I900. E. MCCUNV ILLE. COMPOUND STEAMENGINE.

(Application filed Apr. 20, 1399.) (No Model.) 4 Shuts-Sheet 3.

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No. 640,2l8.

COMPOUND STEAM ENGINE.

(Application filed Apr. 20, 1899.) (No Model.)

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COMPOUND STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent N 0. 640,218, dated January2, 1900.

Application filed April 20, 1899.

To all whom it may concern.-

Be it known that I, EMMETT MoCoNvILLE, a citizen of the UnitedStates,residing at Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inCompound Multiple-Piston Steam-Engines; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art towhich it appertains tomake and use the same.

My invention has reference to improvements in multiplepiston compoundsteamengines and other novel features of construction pertaining to thesame, which will be hereinafter fully elucidated in the specification inconjunction with the drawings and clearly pointed out in the claims.

The object of the present invention is to provide a three-pistoncompound steam-engine having their cylinders parallel on a single bed orframe and the steam communication from the high-pressure to thelow-pressure cylinder connected through the medium of a steam-pipe toboth steam-chests.

A further object of the present invention is to provide extremely simpleand novel lever mechanism for operating the piston-valves through themedium of the connecting-rods and movable bifurcated levers mounted upona double yoke spanning the engine-bed in conjunction with a shiftinglever which operates both the piston-valves simultaneously and which ispositive in its varied shifted positions.

A further object of the invention is to provide differentialrelief-valves in the pistons, located at the opposite end of eachcylinder, for allowing water under extreme pressure to escape quickly.

A further object of the invention is to provide movable piston-headswhich are secured to or integral with the pistons in a headlesssteam-cylinder and also to have said pistonheads skeleton in theirconstruction.

A further object of the invention is to provide a hollow piston-valvewhich is open at its ends for allowing steam to have free access to allparts of a steam-chest.

A further object of my invention is to provide askeleton bed or frameconnected by Serial No. 713,701. (No model.)

light tubesfor supporting the cylinders crank mechanism, and doubleyoke.

In the drawings, Figure l is a plan of my improved compoundmultiple-piston engine. Fig. 2 is a front elevation, enlarged, of thede-' vice. Fig. 3 is a longitudinal vertical section of the devicethrough the low-pressure cylinder, with the pistons in elevation. Fig. 4is an enlarged view of the cylinder proper, with the movablepiston-heads and their accompanying pistons partly broken away, so as toexhibit the differential valves therein. Fig. 5 is an elevation of therear end of the engine. Fig. 6 is a detail of one of the movableskeleton piston-heads. Fig. 7 is a detail of the lever mechanism foroperating the pistonvalves. Fig. 8 is an inside view of one-half of abifurcated lever. Fig. 9 is a section on line 9 9 of Fig. 8.

The invention consists of a bed or frame having the opposite ends A andA of light castings, which are tied together by light steel tubes a.Said tubes support the steam-cylinders B and B through the medium ofbrackets 19. Also secured to said tubes at is a double yoke with itsparts 0 and O for supporting the valve-operating mechanism.

The front casting Aof the bed or frame supports the crank mechanism,which consists of large cranks D and smaller cranks d, respectively.Cranks D support connecting-rods D, which are pivoted to sliding heads Eand E, which are mounted upon rods or ways 6 e. The piston-rods pivotedto sliding heads E and E pass through stuffing-boxes F and F of theskeleton piston-heads G G, thence through the front pistons g and g, andare secured to the middle pistons H and H. The small cranks d carryconnecting bars h and h, which are secured to the forward movablepiston-heads G and G in mortises d (See Fig. 6.) Secured to said bars hand h are lugs t' and i, which carry side bars I and I and which areattached to cross-heads J and J, operating on guides 7c and Each crosshead carries a piston-rod K and K, respectively, which is secured to therear movable piston-heads L and L with their accompany ing pistons G2and G Mounted on each cylinder is a steam-chest M and M, carryingvalve-rods m and m,

which are pivoted to connecting-rods N and N. Said rods are pivoted torocking levers O and 0, (see Figs. 2 and 3,) which are fulcrumed insliding blocks 10, mounted in recesses 19', (see Figs. 2 and 7,) formedin the bifurcated levers P and P. Said bifurcated levers are in twoparts. They are joined together at their upper part by bolts p whichalso act as a pivotal point for the shifting yoke Q, being also securedby said bolts 19 from lateral movement. Bifurcated levers P and P arefulcrumed on trunnionslo which play in bearings c, forming part of yokesG and 0, previously referred to. (See Fig. 7.)

Secured to the lower end of each rocking lever O and O at r are links RandR. The upper ends of said links are secured to the con necting-rodsD. (See Figs. 3 and 7, where only one is shown. The lower ends of saidlinks are seen red to pivotal stay-rods S,which are secured by an ear 5,connected to each cylinder.

Located centrally on the forward part of the bed or frame is a standardT, which carries; an arc plate T, having notches t therein for securinga latch a, which is attached to a bent lever U, making connection withthe shifting yoke Q, said shifting yoke being connected to bothbifurcated levers P and P, whereby the piston-valves in each steam-chestcan be operated simultaneously for starting or reversing the engine. Asonly the steamchest in the low-pressure cylinder is shown in section,with its accompanying valve, and as both valves are exactly alike, Iwill proceed to describe this valve.

As will be observed, the piston-valve 15 is hollow, whereby the steamcan have free access to all parts of the steam-chest. Thereis a neck16formed on said piston-valve, so as 'to allow the exhaust-steam to havefree circulation through opening 20, which is very desirable infast-moving engines. This neck 16 allows a space 1'7 to be formedadjacent to each steam-port 18- and 19 as the valve movesalternatelyover each steam-port.

The high pressure engine receives live steam through pipe 23 andexhausts when cut off into pipe 24, passing throughthe ad= justablecheck-valve 40, connecting with the valve-chest M of the low-pressurecylinder.

25 is the exhaust for the low-pressure cylind-er.

Located in the movable pistons are differential release-valves 26 forallowing any extraneous pressure caused by water or other fluids toescape freely, so as to prevent the pistons being ruptured. The springs27 on the back of these valves can be of any desired tension toaccommodate the steam-pressure,

the area of the large valve-seat being about six times the area of thesmall seat facing the inside of the cylinder.

This engine is designed to carry about eighty pounds of steam, and ifthe valve should be set to openby hydraulic pressure at one hundred andfiftypounds the pressure on the large valve would be only about twentyfive pounds, thus allowing all the fluid to escape at a pressure lessthan the steam-pressure.

Operation of my improved engine, referring in the singular only tothelow-pressure cylinder: As steam enters port 19 it enters thesteam-cylinder between the front piston g and the middle piston H.Consequently each piston is forced in opposite directions, and as themiddle piston H moves backward it draws the large crank D toward saidpiston, and as the front piston g moves forward it pushes the smallcranks (1 forward, and by the time the middle piston reaches the point21 in the cylinder the back piston G which was drawn forward to thepoint 22 by means of the side bars I, securedto connecting-bars h of theforward piston g the valve is shifted and the steam enters the port 18,when the middle piston H and back piston G are forced in oppositedirections. The pistons then assume the position shown in Fig. 3, theback piston G acting through the side bars I to bring the front pistonto the position as also indicated in Fig. 3, this operationbeingrepeated for every stroke of the engine. As the connectingrods playback and forth they operate the lever mechanism, the rocking levermoving by means of its blocks 10 in the grooves 10, formed in thebifurcated levers P and P.

Having described my invention, that which I desire to claim is- 1. Inacompound steam-engine having one high and one low pressure cylinder,three movable piston-heads in each cylinder, the two extreme heads ineach cylinder being skeleton or open heads, but integral with a solidpiston, said pistons having differential valves cooperating with anopening in a solid piston, a distribu tion-v'alve for each cylinder, asteam-pipe connecting the steam-chests of said cylinders fortransmittingsteam from the high to the low pressure cylinder, an exhaust-pipeleading from the low-pressure cylinder, and suitable operative mechanismcon nected to said cylinders and valves for communicating motiontherefrom for the purpose as shown and described.

2. In a compound steam-engine having one high and one low pressurecylinder, three movable piston-heads with pistons integral therewith ineach cylinder, each of the extreme pistons having differential valves, adistribution-valve for each cylinder, a steampipe connecting thesteam-chests of said cylinders for transmitting steam from thehigh tothe lowpressure cylinder, an exhaust-pipe leading from the low-pressurecylinder, and the means for operating said engine through the medium ofits cylinders and valves in combination with a skeleton bed or frame asshown and described for supporting said engine.

3. In a compound steam-engine having one high and one low pressurecylinder, three movable piston-heads in each cylinder, the two extremeheads in each cylinder being skeleton or open heads, but integral with asolid piston, said pistons having differential valves cooperating withan opening in a solid piston, a distribution-valve for each cylinder, asteampipe provided with an adjustable check-valve connecting thesteam-chests of said cylinders, for transmitting steam from the high tothe low pressure cylinder through their steam-cl1ests, an exhaust-pipeleading from the valve-chest of the low-pressure cylinder, the meansconnected to said cylinder and valves for operating said engine asspecified.

4. In a compound steam -engine having open-ended cylinders, one high andone low pressure, three movable piston-heads in each cylinder, the twoextreme heads being open or skeleton in construction, but integral witha solid piston, said pistons having differential valves cooperating withan opening in a solid piston, a distribution-valve for each cylinder, asteam-pipe connecting the steamchests of said cylinders, an exhaust-pipeleading from the steam-chest of the low-pressure cylinder, incombination with a skeleton bed or frame consisting of steel tubes,secured at their free ends to castings for supporting said engine asshown and described.

5. In a compound steam'engine having one high and one low pressurecylinder, three movable piston-heads in each cylinder, the two extremeheads in each cylinder being open or skeleton in construction, butintegral with a solid piston, said pistons having differential valvescooperating with an opening in a solid piston, a distribution-valve foreach cylinder, a live-steam pipe connecting the steam-chests of saidcylinders, an exhaustpipe leading from the steam-chest of thelowpressure cylinder, a double yoke supported upon a skeleton frame orbed, for holding the valve-operating mechanism of said engine asspecified.

6. In a compound steam-engine having one high and one low pressurecylinder, three movable pistons with their accompanying head in eachcylinder, a piston-valve for each cylinder, a live-steam pipe connectingthe steam-chests of said cylinders, an exhaustpipe leading from thesteam-chest of the lowpressure cylinder,a double yoke secured to theskeleton frame or bed, for supporting bifurcated levers pivotallysecured to said yokes, for carrying the valve mechanism which isattached to the movable connecting-rods, as specified.

7. 111 a compound steam-engine having one high and one low pressurecylinder, three movable pistons in each cylinder,stearn-chests anddistribution valves for each cylinder, an exhaust-steam pipe connectingthe steamchests of said cylinders, an exhaust-pipe leading from thesteam-chest of the low-pressure cylinder to the atmosphere, a doubleyoke secured to the skeleton frame or bed, for supporting bifurcatedlevers, pivotally secured to said yokes, for carrying rocking leverswhich operate said distribution-valves and links, the latter beingattached to the movable connecting-rods at one end, the opposite endspivotally secured to movable rods, as shown and described.

8. In a compound steam-engine having one high and one low pressurecylinder, three movable pistons in each cylinder,steam-chests anddistribution-valves for each cylinder, an exhaust-pipe connecting thesteam-chests of said cylinders, an exhaust-pipe leading from thesteam'chest of the low-pressure cylinder to the atmosphere, a doubleyoke secured to the skeleton frame or bed for supporting bisectedbifurcated levers pivotally secured to yokes, for carrying rockinglevers which operate said distributionyalves and links, said links beingattached to movable connectingrods at one end, the opposite ends,connected to pivoted stay-rods, which are hinged to the under side ofthe steam-cylinders as shown and described.

9. In a compound steam-engine having one high and one low pressurecylinder, three movable pistonsin each cylinder,steam-chests anddistributionyalves for each cylinder, an exhaust-pipe connecting thesteam-chests of said cylinders, an exhaust-pipe leading from thelow-pressure cylinder to the atmosphere, a double yoke secured to theskeleton frame or bed for supporting bisected bifurcated levers, whichare pivotally secured to said yokes,

the latter carrying rocking levers which operate saiddistribution-valves which are pivoted to blocks operating in ways orguides formed in the legs of said bifurcated levers, of links pivoted tosaid rocking levers for operating piston-valves through the medium ofmovable connecting-rods as shown and de scribed.

10. In a compound steam-engine having one high and one low pressurecylinder, three movable pistons in each cylinder,steam-chests anddistribution-valves for each cylinder, an exhaust-pipe connecting thesteam-chests of said cylinders, an exhaust-pipe leading from thelow-pressure cylinder to the atmosphere, a double yoke secured to theengine-bed or skeleton frame for supporting bisected bifurcated levers,which are pivotally secured to said yokes, the latter carrying rockinglevers which operate said distribution-valves which are pivoted toblocks operating in ways, formed in the legs of said bifurcated levers,links pivoted to said rocking levers, one end of said links beingattached to movable connecting rods, the opposite ends connected tostay-rods, said stay-rods being hinged or pivoted to the front end ofthe steam-cylinders as specified.

11. In a compound steam-engine having one high and one low pressurecylinder, three movable pistons in each eylinder,steam-chests anddistribution-valves for each cylinder, an exhaust-pipe connecting saidcylinders, and

an exhaust-pipe from the low-pressure cylinder to the atmosphere, ayokesecured to the skeleton bed for supporting bisected bifurcatedlevers, which carry rocking arms, the upper. ends of said rocking leverspivotally secured to the connecting-rods of the pistondistribution-valve stems, the lower ends secured to links pivoted to theconnecting-rods of the steam-cylinders, and also to stay-rods, which areattached to the steam-cylinders as shown and described. 1

12. In a compound steam-engine having one high and one low pressurecylinder, three movable pistons in each cy1inder,steam-chests anddistribution-valves for each cylinder, an exhaust-pipe and check-valveconnecting said

